Speedometer.



UNITED STATES PATENT OFFCE.

ABRAM HOFFECKER, OF BOSTON, MASSACHUSETTS, ASSIG-NOR TO RiELIANCE SPEEDMETER COMPANY, 0E BOSTON, MASSACHUSETTS, A CORPORATION 0F MAINE.

Specification of etters Patent.

srnnnonernn.

Patented Feb. l 7, 1914.

To all 'whom/'it may concern Be it known that I, Annan Horrnonnn, of

Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Speedometers, of which the following is a specification.

This invention relates to instruments for measuring the speeds of movingbodies, and is particularly int-ended for use with vehicles, to show the speed at which they are moving.

The objectof the invention is to simplify the construction of such instruments so as to furnish one having the minimum number of parts consistent with accurate operation and convenient reading of the indications.

The essential features of a speed-measuring instrument are a device put in motion by the movement of the object whose speed is to be measured, and adapted to vary its position in accordance with the speed of the object, an indicator' by which the speed may be shown in terms of units of distance per unit of time, and connections between such variable device and the indicator, whereby the movements of the latter vare governed by the former. By my present invention I have reduced such intermediate connections to the lowest possible terms, and. have produced a mechanism which is accurate, simple in construction, economical to manufacture, and practically incapable of getting out of order. A

In the accompanying drawings I have illustrated an apparatus embodying the principles of my invention, in which,-

Figure 1 represents a plan view of the instrument, showing the dial and indicator. Fig. 2 represents a plan view of the same with the dial plate removed, showing the internal parts. Fig. 3 represents a vertical longitudinal section of the instrument. F1 g. 4 represents a modification of the connection between the disk and rack.

The same reference characters indicate the same parts in all the figures.

The essential parts of the instrument comprise a shafty l' which is 'driven rotarily by the vehicle or other moving object of which the speed is to be determined, a centrifugal governor consisting of two weights 2 2 which are linked to a collar 3 secured to and rotated by the shaft, a pointer 4 operating in connection with a dial 5 to show speeds,

and a disk operated bythe weights and.

engaged with the pointer to communicate movements thereto. The weights are connected by links 7 to lugs 8 formed on the collar, said links being pivoted to the lugs, andby similar links 9 to the disk, the latter vhaving lugs 10 to which said links are pivoted. The weights being thus pivotally connected to the shaft and .to the disk are free to move outward by centrifugal force, and act in the manner of a centrifugal governor. As the speed increases, vthey move farther and farthery away from the shaft, traveling in a variable orbit, the diameter of which increases as the speed increases, until at the highest speed whichthe instrument c n measure, the weights occupy the positions indicated in dotted lines in Fig. 3. In mov- I mg to theseJ positions, the weights draw the shaft with sufficient looseness to permit. movement thereon, but tightly enough to prevent side play'.v The movement of the disk toward the collar 3, and hence the outward movements of the weights, are resisted by a spring 13 surrounding the shaft and bearing against the collar 3 and disk. spring also acts to restore the members to their normal position, illustrated in full lines in Fig. 3, when the vehicle isv at rest or is diminishing in speed. The strength of the spring determines the range of speeds which the instrument is capable of measuring, and by using springs of different tensions, the same or similar instruments may be rendered capable of indicating a great variety of speeds. The motion of the disk 6 along the shaft is communicated to the pointer 4; by means of a slide 14 having a rack 15 meshing with a pinion 16 on the shaft of the pointer; The slide is connected with the disk in such a way as to be unafl fected by the rotation thereof, but to follow every change in the position of the disk longitudinally of the shaft. The preferred connection between the disk and slide is a. stud 17 secured in the slide, projecting therefrom toward the disk, said stud having a slot 18 which receives the rim of the disk and is fitted sol as to embrace the disk with.

ihzlg 1 I gfW me S11/mpi 90% w parts as can be mutiny 1s un. 055CY "2@ bemin' or im Shaft :u2 op 3g la? und h 25 imhuww 1; E :arranged on 90 its si( of SAU mimi@ Y mecod i@ #he hub fm @p9 L); he axis and wunsch 1 re- Y weights, links ids@ com' 3,0 wdl Hw CHUM, Whe.. by 95 1: bled to swing outward@ 'when the shalt 1s 'rrr with `z d mak so zu; ko be ment? ihr-wwf, m ya ,11nd

@Vond me memes movements of the latter along the shaft are transmitted to the rack, and a screw. thread ed into one of said abutments, engaging said spring, and being adjustable to vary the tension thereof.

3. A speed-measuring instrument comprising a cylindrical casing, a shaft crossing said casing transversely of the axis thereof, a guide crossing said casing parallel to said shaft and contained within v the casing, an indicator pivoted coaxially with said casing, a centrifugal governor carried by saidshalt, a rack mounted to travel on said guide and supported Wholly thereby, and means connecting said rack with said governor and indicator.

d. A speedometer comprising a shaft, a guide bar mounted beside and approximately parallel to said shaft, a centrifugal governor carried and rotated by said shaft, a traveler linked to said governorv and moved by the latter longitudinally along the shaft, a .rack having a portion embracing said'har, connected with said traveler so as to he moved hy the longitudinal movements of the latter, a spindle havin@ a pinion in meshwith said rack and located so as to retain the latter on the guide bar, and an indicator carried by said spindle. y

5. A speed indicator comprising a rotating shaft, a disk mounted to travel longitudinally on. said shaft, a centrifu'al governor linked to said shaft and disk and operable to move the latter along the shaft, an indicatingpointer, and an intermediate operating device for said pointer including a slide and a projection on said slide arranged toenone ffice or' said disk near the rim thereof, said projection having a yielding said governor so as to be movedaxially of the vshaft thereby, 'a spring for resist-ing the action of the governor, a sleeve threaded into the disk forming a bearing for the latter lon the shaft` and constituting an abutment to take the thrust of said spring, said sleeve b'eing adjustable .to adjust the spring a pointer, and an 'intermediate connecting means between said pointer and disk whereby the movement .ot the latter longitudinally'of the shaft actuates the former to indicate speeds.

7. In a speed-measuring instrument, a shaft, a collar secured to said shaft, a disk mounted so as to slide longitudinally on the shaft, a sleeve surrounding the shaft and threaded into said disk so as to be adjustable axially therein, governor Weights linked to said collar and dislna spring surrounding the shaft and bearing between said coller and sleeve, a flange on the sleeve, stherebj7 the latter may be adjusted, and a sprin pressed pin engaged with the disk and Witv said flange for securing the sleeve` in its ad justin/lents. In testimony whereof l have atlixed my signature, .in presence of tvv'o witnesses.

ABRAM HOFFECKER. Witnesses A. H. Bunn, PETER W. PEzzn'r'rr, 

